The property tycoons behind London's most lavish residential development are £62m better off after fresh details emerged of sales at One Hyde Park.

The Candy brothers, Nick and Christian, and their backers have pocketed the sum after selling one sixth floor property for £22m, and one on the second floor for £21.6m. A third has sold for £14.85m while another buyer seems to have secured a bargain, paying just £3.8m for a second floor apartment in the Knightsbridge complex.

As one might expect from what the estate agent's blurb describes boldly as "the most exclusive address in the world", the title registers for the properties make clear that all come with designated wine storage space. Owners are also treated as permanent guests of neighbouring, Mandarin Oriental, the 5-star luxury hotel which boasts "legendary" service according to Knight Frank. They also get access to a private cinema, a 21-metre swimming pool and a squash court, among other amenities.

Details of the four flats have emerged on the Land Registry. Until now only two completed sales had been made public, but as one of them was to a backer of the scheme and another to one of the brothers, the latest sales are the first indication of a genuine price.

Mystery surrounds the identity of the buyers of three of the flats since they have been bought through offshore trusts. The exception is the second-floor flat which was sold for £21.6m to Paul and Jill Barley, who also own a £2m country pile in Enton in Surrey. There is little public information available on the pair, other than that he is in his early 40s. He describes himself as self-employed, but it is unclear what either do for a living.

The £22m apartment on the sixth floor has been sold to a company called Vamespark Investments Corporation, incorporated in the Republic of Liberia.

A third apartment is now registered to a Guernsey company called Stag Holdings, incorporated in Guernsey. Stag Holdings paid £14.85m for the third-floor property.

The last of the four is registered to Guernsey company PC Holdings Limited – its owner paying just £3.8m for the flat, in a block where the lowest price had been expected to be £6.5m.

While the sales cannot confirm the heady figures being claimed for the development, experts suggested that the figures were in the right ballpark. They suggested that even the £20m apartments were on the cheaper side for the development. Flats facing Knightsbridge rather than Hyde Park, and on lower floors, are cheaper.

A penthouse flat in the development is understood to have been sold for £135m, but Land Registry documents have yet to be filed. The owner is set to spend a further £50m on interior work, it is thought, but even without those extra works it would become the most expensive home ever bought in the UK.

A spokeswoman for Candy & Candy declined to comment on the latest figures, saying only that deals on 40 apartments have now been completed, bringing the total value of completed deals to £900m. The Candy brothers are almost able to repay the £1.1bn they borrowed from Eurohypo Bank to finance the development.